Computers have become an integral tool used in a wide variety of different applications, such as in finance and commercial transactions, three-dimensional and real-time graphics, computer-aided design and manufacturing, healthcare, telecommunications, education, etc. Computers are finding new applications as performance and speeds ever increase while costs decrease due to advances in hardware technology and rapid software development.
As is known in the art, large mainframe, or host, computer systems require large capacity data storage systems. These large mainframe, or host computer systems generally include controllers and software which perform many operations on data introduced to the computer system through peripherals including the data storage system. The results of these operations are output to peripherals, including the storage system.
FIG. 1 is a block diagram of a conventional data storage system 100. The data storage system includes a host computer 110, embedded software 120, first and second controllers 130, 140 and first and second hard disk drives 150, 160. The first and second hard drives 150, 160 are respectively coupled to the first and second controllers 130, 140 wherein the first and second controllers 130, 140 are coupled to the embedded software 120.
During operation, the host computer 110 has separate access to the first and second hard drives 150, 160 via the software 120 and the first and second controllers 130, 140 respectively. Sometimes, however, a system user will need to increase the data storage capacity of the existing system. In order to accomplish this, the user will have to purchase not only the hard drive, but must incur the cost of software and a controller along with the related electronics. Consequently, the cost of adding storage to the system will exceed the cost per megabyte of memory based on the cost of the software and the controller.
Accordingly, what is needed is an expandable data storage system whereby the cost of adding storage to the system is as close to the actual cost per megabyte of memory being added as possible. The data storage system should be simple, cost effective and capable of being easily adapted to existing technology. The present invention addresses these needs.